Transformers: Falling for the enemy
by Serenia pax
Summary: The war is still fierce for the autobots as they try to save earth. However, disaster strikes as sideswipe is killed in battle and a new femne comes into view. Now sunstreaker is faced with a choice, choose the femme he loves or the autobots.
1. chapter 1: Battle cries

**Summary:**

The war is still fierce for the autobots as they try to save Earth. However disaster strikes as sideswipe is killed in battle and an old enemy of cybertron comes into view. Now faced with a choice sunstreaker must choose the femme he loves or the autobots.

Ps.This is my first time so don't expect to much.

 **Chapter 1: Battle cries**

"Sideswipe, sunstreaker, Ironhide your needed at the main hanger!" Sam shouted the three autobots in a rather impatient tone.

Sunstreaker vented a sigh as the groundbridge opened and the small team led by optimus, entered what was meant to be a energon cavern. "Optimus how kind of you to pay us a visit on such sort notice" megatron smirked. "Megatron...autobots stand your ground!" Prime yelled before charging at megatron whilst the rest of his team dismantled any con who came their way.

"Still a load of slag, eh sunny!" Sideswipe cheered, "Don't call me that an- SIDES BEHIND YOU!!" but it came to late as sideswipe was stabbed in his spark chamber by barricade.

 **Sunstreaker POV:**

Time froze around me at that moment..my brother was just killed in front of me and I couldn't save him, not now. "Sunstreaker hurry! Retreat!" snapping out of my trance I saw the remaining autobots running for the exit and so I did my best to catch up. However soon after escaping from the 'cons the others were gone and I was left stranded in the forest.

...:Sunsteaker here any one there?...:

...:silence...:

Soundwave must be blocking the transmission looks like my best option is to find the others myself. I started to walk around hoping to run into the others however I was still in too much a state of shock to navigate and think right.

 **(With megatron)**

"Lord Megatron there is no sign of the autobots" megatron merely chuckled at the vehacons words."Send out a squadron to hunt them down and bring them to me alive."It wouldn't be long now and the last of the primes would fall to his demise. The vehacon bowed in acknowledgment and took to the skies with a small group of deception soldiers.

 **With Optimus and Ironhide**

Optimus and ironhide were resting beneath an old oak tree."We must find sunstreaker before the cons can..." ironhide was out of breath and would run out of energon if he didn't rest, Optimus new this and was not willing to lose a second comrade that day." Ironhide I know you are worried but we can not find sunstreaker on such low energy, our best option would be to wait for ratchet to send back up -and he will- before letting Arcee and bumblebee look for sunstreaker." a sigh could be heard escaping ironhide's vent but he new his leader was right and allowed himself to fall into recharge.

 **What will happen?**

 **Will the autobots find sunstreaker before the deceptions or will someone else find him?**

 **Will he be alright or will his actions lead to his demise?**

 **What is megatron planning to do?**


	2. Chapter two: The new femme

**Chapter 2: The new femme**

 _ **With Sunstreaker**_

 _"Ugh it's useless I'm never gonna find anyone at this rate!!"_

 _"Oh I wouldn't say never sunstreaker..."_

 _Sunstreaker jumps at the sudden voice."Who are you..?" A low chuckle could be heard from the shadows as a femme about sunstreaker's size emerged from her hiding spot.She was a silver grey with dark blue optics, the stranger was thin and showed a clear past of battle by the scar on her side. As Sunstreaker looked at the femme he noticed the autobot insigma on the back of her hand._

 _"Your an autobot?"_

 _"Hmm, oh yes names Tronisa I just got here yesterday"_

 _"How?"_

 _"I was leaving cybertron ,like everyone else, when a Decepticon knocked me out. When I woke up I was on the 'Cons ship but I managed to give the guard the slip and hop in an escape pod. Apparently it was a long distance pod because I was put into status. When I wake up I'm on solid ground."_

 _"I see...by the way I'm sunstreaker, but you already know that"_

 _"Yeah...being on team with prime you do become easier to notice."_

 _ **With Megatron**_

 _"Lord Megatron why are you trying to capture the autobots when Tronisa is infiltrating their base?"_

 _"Because Starscream, if I simply let them go without a chase the exact same time a new femme just happens to appear it will raise suspicion. Suspicion that will put a halt on my plans."_

 _"I see. Thank you master." Starscream bows and leaves._

 _ **Megatron's POV:**_

 _That and I won't have Tronisa be discovered by prime. She may be a capable warrior but I won't let Optimus take her from me._

 ** _Autobot base_**

 _"Arcee, bumblebee, jetfire and jazz once you find the others get back to base immediately."_

 _Ratchet opens the groundbridge and the team goes through._

 _ **With Optimus and Ironhide**_

 _"We won't last much longer out here on such low energon especially if the Decepticons find us."_

 _"Yes but we must wait for the others."_

 _Ironhide mumbles under_ _his breath and continues to watch the sky for any Decepticon squads. Optimus however, keeps a look out for any of the team searching for them._

 _"Prime, Ironhide!!"_

 _Both bots look to see Jazz and Jetfire coming over to them. Jazz quickly takes Ironhide and Jetfire takes Optimus._

 _"Ratchet we got Optimus and Ironhide, open the groundbridge"_

 _The groundbridge opens and the four mechs go through._

 _ **At the same time with Tronisa and Sunstreaker**_

 _"Well it's not like I have anything better to do."_

 _Tronisa sits next to Sunstreaker and the pair begin to talk as a way of passing the time, waiting for the other autobots to find them._

 _"So got any siblings?"_

 _"Used to have an older brother, he died in battle back on cybertron. Tronus was an excellent fighter. But what about you, don't you have your twin Sideswipe?"_

 _"No Sides he... died earlier today..."_

 _" I'm so sorry Sunstreaker I didn't know..."_

 _Suddenly Tronisa hugs Sunstreaker. Sunstreaker hesitates but returns the embrace, resting his helm on top of her's._

 _"we just met and you already know how to make me feel better, are you sure you don't know everything about me?"_

 _A soft laugh comes from Tronisa as she hugs him a bit tighter before letting go and pulling away._

 _"I'll take that as a compliment"_

 _Now it was Sunstreaker's turn to laugh as Tronisa began keeping a look out for any sign of company._

 _ **With Arcee and Bumblebee**_

 _"He's gotta be here somewhere..."_

 _The two cautiously look for Sunstreaker whilst making sure not to be found by any 'Cons. Then out of nowhere gunshots are heard from further on._

 ** _With Sunstreaker and Tronisa_**

 _The two were sat in silence until Tronisa suddenly fell forward, unconscious. As Sunstreaker turned to see what had happened he saw a group of vehacons standing right behind him._

 _"Scrap!"_

 _Moving quickly Sunstreaker managed to barely dodge the shots fired at him as he tried to draw their fire away from Tronisa's unconscious body._

 _"SUNSTREAKER !!"_

 _Sunstreaker turns to see Arcee and bumblebee running, taking down every decepticon who crossed their path. With their help the vehacons were delt with as Sunstreaker checked Tronisa before lifting her back to the others._

 _"Who is she?"_

 _"Her name is Tronisa, Arcee and she's a friend"_

 _Arcee simply nodded and commed Ratchet for a groundbridge. Within a couple of minutes the bridge opened allowing them to pass through into base._

 **What will Tronisa do now?**

 **Will Optimus recognise her?**

 **How will the team react to her?**

 **Next chapter coming soon!!!!**


	3. Chapter three: Meetings

**Chapter 3: Meetings**

After bridging the remaining bots back to base Ratchet quickly had everyone found examined for wounds and repaired. Meanwhile Tronisa had been placed on a medical berth till she was able to regain consciousness. But what no one had paid attention to is that she was awake as soon as someone had put her on the berth. So sick of waiting she put on her best face of confusion and pain on and slowly got up.

"Uggg... my helm, what happened?"

At the sudden sound of her voice Sunstreaker jumped off his medical berth and was next to Tronisa before Ratchet could even turn around.

"Tronisa are you ok?"

"Sunstreaker..? Ya I'm fine just a little dizzy, where are we last thing I remember is being with you in the forest then nothing..."

"Oh yeah, a vehacon knocked you out from behind. We're in the autobot base and right now in the medical centre waiting for Ratchet to check for wounds."

"Which I can't do if you are in the way! Now go back to your berth and rest Sunstreaker so I can check your friend here."

Giving a disappointed grunt Sunstreaker lay back down on his berth while Ratchet introduces himself and checks her for injuries.

 **Tronisa's POV:**

Once excused from the med bay me and Sunstreaker began to head to the command room where everyone was waiting. I kept close to Sunstreaker the entire way not just to act the part of 'new bot' but because I was nervous. It had been eons since I last saw Prime and although the image enhancer was working aka: my dark blue highlights and the red gem above my chest were hidden, I was still scared he would recognise me. At that thought I straightened up. There was no way he would know it was me after all the image enhancer was made by shockwave of all Decepticons. But I couldn't shake the feeling something was just not right. The sound of a light cough brought me back to reality.

"We're nearly there and don't worry there a bit rough round the edges but are completely safe, well more or less."

'Completely safe, more or less' I'm not a sparkling for pits sake and I doubt it can be worse than the Decepticons, he seems to forget I've seen war just as much as he has.

"Thanks, I know I'm just a bit nervous meeting new people"

"You nervous? I wouldn't have thought the way you acted when we met."

"Ya, well I'm fine if it's just one or two just not crowds."

I look to see Sunstreaker give me a soft smile so I return it as we continue walking. _'Why is he being so nice to me after all we just met today..' quickly dismissing the thought I get back to the job at hand._

 **Ironhide's POV:**

We were all waiting for the new femme to come through with Sunstreaker. ' _Primus where they?!'_ Just as I was about to suggest looking for them a soft giggle could be heard as the two walk into view smiles on there faces.

"Sunstreaker."

"Prime this is Tronisa, Tronisa Optimus Prime"

I watched as the two are introduced and begin talking, Sunstreaker never once leaving this 'Tronisa's' side.

"Optimus Prime It's an honour to meet you."

"And you Tronisa... Please this may seem odd but have we met, you look so familiar"

"No, I believe this is the first time we have ever met"

Wrong answer, Optimus never forgets a face which means she's up to something.

"I see but I still rarely forget a face, I must have seen someone like you back on cybertron."

"Yes that would be the most logical reason."

Most logical reason?! That's it I'm convinced she's a spy. She obviously spends a lot of time around Shockwave to talk like that and no autobot's face is emotionally empty when speaking.

"Yes, well in any case I hope you feel welcome here and at home."

"Thank you Prime, I will"

 **Third person POV:**

After Sunstreaker left with Tronisa to show her the base and her room conversation finally broke out.

"She seems nice"

"Perhaps mikalea but if you ask me she was a bit too eager to escape the introduction with Optimus"

"I agree Ironhide Tronisa seemed very uneasy.."

"Ironhide, Ratchet your concern is noted but she may just be uncomfortable in the new environment."

"Prime please, if you ask me she's a no good spy."

"Ironhide! She just got here how do you know what she is and what she isn't?!"

"Instinct."

Mikalea rolls her eyes and walks of.

-mini time skip-

 **With mikalea**

The nerve! She just gets here and Ironhide already think she's a spy. I was just about to march back and yell some more when I heard a soft voice from the training room.

 **Third person POV:**

When turning to the training room mikalea noticed she was alone short of Sunstreaker who looked more dazed than anything else. Then in the middle of the room stood Tronisa completely unaware of her viewers as she practiced fighting stances and unique battle skills. The way she calmly yet fiercely kept every move in sync to the song made it look as though the talent for war was some sort of dance. It was then Mikalea noticed the song that she was singing.

 _You've got the words to change a nation, but your biting your tongue._

 _You've spent a lifetime stuck in silence afraid you'll say something wrong._

 _If no one ever hears it how we gonna_ _learn_ _your song so come on, come on._

 _You got a heart as loud as lions so why let your voice be tamed._

 _Maybe we're a little different it's no reason to be ashamed._

 _You've got the light to fight the shadows so stop hiding it away._ So come on, come on.

 _I wanna_ _sing_ , _I_ _wanna_ _shout_ , _I_ _wanna_ _scream_ ' _til_ _the_ _words_ _dry_ _out_. _So_ _put_ _it_ _in_ _all_ _the_ _papers_. _I'm_ _not_ _afraid_. _They_ _can_ _read_ _all_ _about_ _it_. _Read_ _all_ _about_ _it_ , _oh_

 _Oh_ , _oh_ , _oh_

 _Oh_ , _oh_ , _oh_

 _Oh_ , _oh_ , _oh_

 _Oh_ , _oh_ , _oh_

 _Oh_ , _oh_ , _oh_

 _Oh_ , _oh_ , _oh_...

Finishing her practice Tronisa stops singing and stands up straight before noticing her audience.

 **Tronisa's POV:**

'Scrap! How long were they watching if they saw me practicing.. no remember there is no way they would know the fighting type.'

Composing herself mentally Tronisa began to cover up what she was doing before they did anything drastic.

"...How long were you there?"

 **Sunstreaker POV:**

I can't believe what I just saw... Tronisa makes fighting look like angels work...

"...How long were you there?"

"Hu?!Oh..Not long Tronisa about ten minutes.."

"I see and what about you um?"

"Mikalea. Don't worry I have only been here a couple of minutes."

It was now I noticed the small human in the room. I must have been so preoccupied by Tronisa's training that I didn't notice.

Then I looked again to see mikalea leaving and Tronisa walking toward me.

"C'mon I finished training and need some fresh air"

"Course and anyway someone's gotta make sure you get an alt mode beautiful."

 **Tronisa POV:**

'Typical Suns already acting like a flirt hmm...this could yet work to my advantage..'

"What ever you say Suns"

 **Third person POV:**

Both Sunstreaker and Tronisa left base unaware there conversations were being listened to abord nemesis.

 **Nemesis**

 **Megatron POV:**

"Thank you Soundwave that is enough.."

Soundwave bows hi head and leaves the bridge.

"Lord Megatron"

"Yes starscream?"

"The troops know that for the next three months Tronisa is to be treated like an autobot in the presence of her new 'team' "

"Excellent, everything is coming into place"

"But...What if she figures out her past?"

"She won't, is that understood?!"

"Y-Yes my lord"

Starscream quickly bows and hurried out of the bridge.

'I refuse to lose another sibling to the autobot cause'

 **With Sunstreaker and Tronisa**

 **Third person POV:**

"So.. what do you suggest for a vehicle form"

"I suggest a fast car.."

"Hmm.. and what vehicle mode would you have?"

"Lamborghini"

"Nice. What about that one."

 **Sunstreaker POV:**

I looked to see a Venom GT (270 mph).

"Wow you got taste."

"I'll take that as a yes."

 **Third person POV:**

Tronisa scans the vehicle and transforms into the car.

"Race you back to base?"

"Your on Tronisa"

Once Sunstreaker transforms they readied for the race.

"On three?"

"On three"

"Ok then... Three!"

"Hey! Oh, it's on Sunstreaker!"

 **With Optimus**

 **Optimus POV:**

Where have I seen her before...Tronisa... the only person I know who is called that is.. no they don't even look the same besides little Isa was kidnapped eons ago and is probably dead. I just have to accept the fact they look similar and are not the same Isa is dead and isn't coming back.

 **Is Tronisa and Isa the same?**

 **What is Megatron hiding from Tronisa?**

 **Will Tronisa find the truth?**

 **What will happen between Sunstreaker and Tronisa?**

 **Next chapter coming soon!**


	4. Chapter four: Kidnapped

**Chapter** **four** : **Kidnapped**

"Optimus there's an incoming transmission coming from nemesis."

"Megatron.. Ratchet put it through."

Ratchet nods and steps aside allowing prime to speak.

"Ah, brother."

"What do you want?"

"Such a way to speak Optimus you of all people should know how to treat siblings."

"Leave her out of this"

"I would if I could. Come to the following co-order nets (is this how you spell it?) and come alone."

"Why"

"Because it's about Isa and you know I would never bring her into this if it wasn't important."

 **Optimus POV:**

'Did I just here right? Isa? If he knows something I have to go I can't let this pass.'

"I will be there in one hour."

"Excellent Prime."

I ended the transmission. Ratchet looked like he was going to say something but I simply put my hand up telling him I made my decision. Now I only need to wait...

 **No ones POV:**

As everyone started to come back to the main hanger Sunstreaker and Tronisa race through the door. As they transformed Sunstreaker started yelling about how he should have won the race.

"Woah wait _she_ beat _you_ at a _race?!_ "

"Ya she beat me. But mark my words bee I'll win next time!"

"Sure you will Suns~"

"I will Tronisa! I was just going easy on you!"

Tronisa just stands and laughs while Sunstreaker has a small smile on his lips.

Everyone else merely stands there shocked.

"Sunstreaker are you ok?"

"Of course arcee why wouldn't I be?"

"It's just I didn't think you would be so you after what happened.."

Sunstreaker paused before walking over to Tronisa and puts his arm around her waist.

"Sure I mean Side was my brother I'm never going to be great with the fact he's gone but... Tronisa do you mind if I tell them?"

The femme shakes her head telling him to continue.

"Well Tronisa here lost her older brother during the war and I suppose just talking about it and having her listen and understand just y'know."

This caught prime's attention.

"You lost your brother?"

"Yes.. He was an excellent fighter and always looked out for those he cared about."

"What was his name?"

"..Tronus"

"I see I'm sorry for your loss.."

 **Tronisa POV:**

As I looked into primes optics I saw he was truly sincere but why? Why are they all so nice? I thought Megatron said they were dangerous so why am I actually wanting to be friends with Sunstreaker? Megatron wouldn't lie to me... right? I know I'll be friends with them and see if I can get them to join the decepticons. The less troops prime has the easier he'll be to defeat and I won't be conflicted with emotions. As for his sincerity prime can forget it after all he did leave me for dead.

"Thank you but it happened a long time ago. I do miss him but dwelling on the past won't bring back him or the ones lost."

-Half an hour later at the appointed co-order nets-

"Megatron?"

Suddenly Optimus is knocked out from behind and dragged through a newly opened groundbridge.

 **Who took Optimus, was it the decepticons?**

 **How will the team react?**

 **Will they be able to survive without their leader?**

 **New chapter coming soon!**


	5. The truth and new beginnings

**Chapter five: The Truth and new beginnings**

 **-on nemesis-**

 **No one POV:**

"Do you know what happened to Isa?"

"She's dead."

Megatron laughed at Primes statement.

"Actually she's alive. You see her kidnappers never killed her so when I found her Isa was filled in on all she had missed. Only she thinks we both were told and you never went to retrieve her and continue to believe I didn't either. Really it was the perfect plan to bring your downfall."

 **-15 minutes earlier-**

"We have a fix on Optimus' co-order nets. Opening the groundbridge."

The team ran through scouting the ships halls before making their way to the cells just in time to hear Megatrons confession. Tronisa stood in shock as the team froze and gave her reassuring looks as if to tell her they understood why she did it and didn't blame her. All accept Ironhide and Sunstreaker who glared at her and stood scowling.

"Good to know the truth about why you saved me."

The brothers looked at Tronisa surprised.

"Isa?!"

While he was distracted Jetfire knocked him out untying prime. Then using a unguarded frequency called Ratchet.

"Ratchet bridge."

 **-time skip-**

"Everyone Tronisa is staying here."

Nodding their heads the team agreed as Tronisa walked to the roof.

"You lied."

"Sunstreaker!"

"Ya it's me."

"Listen I know I lied but-"

"But what?! You wanted me dead?!"

"No! I was scared of being caught and all I had been told showed me I'd be killed if that happened!"

"Oh so that's the reason."

"Yes!"

"To think I trusted you... Let me guess the ambush was your idea too!"

"Of course not! You think I wanted Side-"

Tronisa stopped as Sunstreaker slapped her.

"Don't say his name!"

"I didn't know what I was doing! Don't you understand that."

"Enough your just a lying peace of Slag!"

"You know what, get fragged Sunstreaker! Out of everyone I felt closest to you infact I was going to go to you for help before Optimus was abducted. But no you can't even listen to me now."

"Of course not why would I? After all I HATE YOU!!!"

She took a breath at his statement and even Sunstreaker looked shocked at his choice of words.

"Fine if that's the case keep away from me and I'll keep away from you."

Before he could stop her she ran of.

 **Sunstreaker POV:**

No... why did I say that?

 **-2 weeks later-**

 **Tronisa POV:**

I have to leave I don't belong in this war. That and I can't be in the same place as Sunstreaker anymore. Writing a note I explained why I couldn't stay any longer giving them my comlink frequency and began packing.

"Your leaving?"

I turned to see Sunstreaker in my room.

"Yes what of it?"

Without warning he came up and kissed me.

"Because I didn't mean what I said and I would be crushed without you... I love you."

He wiped away the tears in my eyes as I kissed him. He returned it and we soon began a heated embrace.

"Come with me."

"On one condition."

I nodded.

"Be mine?"

"Yes."

 ***LEMON WARNING/**

Smirking he pressed his lips to mine as he backed me down on the berth. Removing my port he began drawing circles with his finger before thrusting two in.

"S-Sunstreaker..."

I couldn't help the moan that passed my lips as he sucked my neck wires whilst continuing to thrust into me. But before I could come he pulled his fingers out of me and started licking my port. Reaching my climax I came, him licking my fluids.

"Enjoying it so far?"

Grinning I flipped him over as he releases his cable. Stroking it I earned some moans and grunts before I began pumping it both of us in an intense kiss. Then leaning down I took him in my mouth and began sucking.

"Tronisa...ugh...frag yes...

He came and I just swallowed everything like he had me. Pinning me back under him Sunstreaker rammed into me causing me to let out a scream of pain and pleasure. This continued till we both came screaming each other's names.

"TRONISA!!"

"SUNSTREAKER!!"

 **-a month later-**

"I have news."

Sunstreaker looks at me from his energon. The ship we had was on autopilot.

"Yes?"

"I'm with spark."

Dropping his energon Sunstreaker picked me up spinning me around.

"Tronisa that's great!"

Smiling we kissed. And I sent the news to Optimus and the team. Jetfire answered though saying Optimus almost passed out and went to rest. Typical. Still I wouldn't change this life for anything.


	6. AN

**A/N**

 **That's it! Sorry it was really short and crappie it was my first story. Still I hope you liked it and I'd love to hear your opinions on it. Any ideas on how to improve would be greatly appreciated.**

 **Bye!**


End file.
